Article ID: MXB1113
Created: 1 Nov 2017
Reviewed: 10 Dec 2017
Information in this article applies to:
How do I change the objective on my uScopeMXII?
There are a number of steps involved in changing the objective in the uScopeMXII. To get started you must:
You should perform the following disassembly on a solid surface.
Please take all necessary precautions to avoid ESD/static damage to the cameras and control board inside the uScope.
Be careful when screwing the objective into the RMS adapter, extension tube, and mirror cube to avoid cross-threading. There are numerous web-based references and Youtube videos that provide more information on how to avoid cross-threading.
Remove the four screws from the corners of the back panel on the uScope. These screws are torqued to specification and may be difficult to remove.
A metric 2.5mm hex driver is required to remove these screws. A complete set of high-quality ball drivers is available from Amazon.
When the rear panel is removed, the back end of the uScope mechanism is exposed.
It is important that you are careful to avoid lifting or moving the uScope mechanism by the light path (the objective, light cube, or tube) to avoid introducing alignment problems.
The two camera boards and control board are sensitive to static electricity. Please observe ESD precautions.
Use your index and middle fingers to pull on the aluminum post to extract the mechanism from the uScope case.
Be careful not to pull on any wires connecting the motors and sensors to the control board. These wires are very small.
Make sure you have plenty of working space to fully slide the mechanism out of the case. The assembly slides easier the further it comes out of the case.
Avoid grasping the light tube to help remove the mechanism. The light tube floats and (while it isn't easy) can be bent out of alignment.
Once the mechanism has been extracted from the case, position it so that you have access to the objective lens assembly.
The objective is located at the front of the mechanism and is hanging down below the mirror cube.
The objective is coupled to an extension tube using an RMS adapter. These components form the objective assembly which must be removed from the mirror cube.
The objective assembly is screwed into the mirror cube.
Carefully, unscrew the assembly from the mirror cube. It may take a quick twist to break the objective assembly loose from the mirror cube.
The objective assembly (removed from the uScope) is pictured. This assembly is composed of three parts:
You must disassemble the objective assembly into its component parts to replace the objective. Be careful as the nose of some objectives is easily unscrewed.
You may need to use a rubber jar pad, rubber gloves, or rubber bands to help get a good grip on the components of the objective assembly.
Do not use pliers or wrenches to unscrew the extension tube or RMS adapter. They will mar the finish and potentially damage the threads.
Using the new objective, reassemble the objective assembly using the objective, RMS adapter, and extension tube. Be sure to screw these components together securely.
Be very careful as you screw the RMS adapter onto the objective and then into the extension tube. It is fairly easy to cross thread the objective and/or RMS adapter.
Carefully screw the objective assembly into the bottom of the mirror cube. Make sure the objective assembly is securely screwed into the cube.
Avoid cross-threading the objective assembly into mirror cube. Screwing the assembly into the cube should be smooth and easily accomplished.
Starting the assembly into the cube by unscrewing may help locate the entry thread to get the assembly started.
To reinsert the mechanism into the case, start by placing the rubber feet just inside the case. Then, slowly slide the mechanism into the case while resting the back end of the mechanism on the work surface—this helps the mechanism slide more easily.
The key here is to be patient and slide the mechanism slowly. Trying to insert the mechanism too quickly could cause the isolation bumpers (the rubber feet) to pull out of their sockets.
Pay close attention to the camera cable on top of the mechanism near the front. This can catch or snag on the top of the case as the mechanism is inserted.
If the cable is too high to slide into the case without getting snagged, you can press it down so that it fits. The cable is very flexible.
When the mechanism almost fully inserted into the case, you may need to lift the base to get the rubber feet on the bottom to clear the edge of the case.
Finally, replace the four screws in the corners of the rear panel and tighten them securely.
You may now reconnect the uScope to power and USB.
After replacing the objective, you must load calibration data for that specific objective.